KR102050503B1 - Optically addressed spatial light modulator divided into plurality of segments, and apparatus and method for holography 3-dimensional display - Google Patents

Abstract

Disclosed are an optical addressing spatial light modulator divided into a plurality of segments, and a holographic three-dimensional image display device and method using the same. The holographic three-dimensional image display device includes a recording light source for emitting a recording beam, an EASLM for modulating the recording beam emitted from the recording light source according to the hologram information divided into a plurality of regions, a reproduction light source for emitting the reproduction beam, and an EASLM. OASLM comprising a plurality of segments for receiving the recording beam modulated by the modulated and modulating the reproduction beam emitted from the reproduction light source according to the hologram information contained in the modulated recording beam, a plurality of segments of the OASLM recording beam modulated by the EASLM Scanning optical unit for transmitting to a corresponding position among the, and Fourier lens for generating a stereoscopic image by focusing the reproduction beam modulated in OASLM in a predetermined space.

Description

Optically addressed spatial light modulator divided into multiple of segments, and apparatus and method for holography 3-dimensional display}

The disclosed embodiments relate to an optically addressed spatial light modulator (OASLM) divided into a plurality of segments, and a holographic 3D image display device and method using the same.

Recently, in various fields such as movies, games, advertisements, medical imaging, education, military, and the like, there is a great demand for a three-dimensional image display device capable of representing images more realistically and effectively. Accordingly, various techniques for displaying 3D images have been proposed, and various 3D image display apparatuses have been commercialized. The 3D image display device that is currently commercially used uses binocular parallax of two eyes, and a viewer can feel a stereoscopic feeling by providing a left eye image and a right eye image having different viewpoints, respectively. Make sure Such 3D image display apparatuses include an eyeglass type 3D image display apparatus requiring special glasses and an autostereoscopic 3D image display apparatus that does not require glasses.

However, in the case of stereoscopy using binocular disparity, eye fatigue is high and only two viewpoints of the left eye image and the right eye image are provided, and thus the change of viewpoint due to the movement of the viewer is not reflected. Therefore, there is a limit to providing a natural three-dimensional effect. Holographic three-dimensional image display technology has been studied to improve the limitations and to display three-dimensional images more naturally.

The holographic three-dimensional image display technology uses a principle in which an image of an original object is reproduced when the reference beam is diffracted by irradiating a hologram that records an interference pattern obtained by interfering a laser beam reflected from the original object and a reference beam. Holographic three-dimensional image display technology, which is currently in practical use, provides a computer-generated hologram (CGH) as an electrical signal to a spatial light modulator, rather than directly exposing an original object to obtain a hologram. The spatial light modulator diffracts the reference beam according to the input CGH signal, thereby generating a 3D image.

In this holographic technique, the performance of a spatial light modulator is important for the reproduced three-dimensional image to have sufficient resolution and viewing angle (ie, to have a large space bandwidth product). For example, a spatial light modulator having approximately 10 ¹⁰ pixels in an area of about 100 cm 2 is required. The commonly used electrically addressable spatial light modulator (EASLM) has a limitation in reducing the size of the pixel because the driving circuit and the wiring are arranged for each pixel, so it is difficult to satisfy the above requirements. Accordingly, a holographic three-dimensional image display device using an optical addressing spatial light modulator (OASLM) has been proposed. The optical addressing spatial light modulator OASLM includes a photosensitive layer disposed on the incident surface of the recording beam, so that only the pixels in the region where the recording beam is incident can be selectively turned on. The optical addressing spatial light modulator OASLM does not require a separate driving circuit and wiring, thereby satisfying the above-described resolution requirements.

On the other hand, a very large amount of computation is required to generate the high resolution CGH required to reproduce the high resolution 3D image. Accordingly, various CGH generation methods and optimization methods have been proposed to reduce the amount of calculation required for CGH generation. One of them is an active that divides an optical addressing spatial light modulator (OASLM) into a number of small tiles, and generates CGHs for each of the relatively low resolution images corresponding to each tile and sequentially provides them to each tile. It is a tiling method.

An optical addressing spatial light modulator (OASLM) divided into a plurality of segments having a small gap between segments, and a holographic three-dimensional image display device using the same.

The present invention also provides a method for displaying a holographic 3D image using the optical addressing spatial light modulator (OASLM).

An optical addressing spatial light modulator according to one type of the invention comprises: a plurality of segmented light modulation segments arranged in a two dimensional array; A gap formed between the plurality of segments; And a plurality of independent transparent electrodes and wires individually allocated to the plurality of segments such that the plurality of segments are independently turned on / off.

The optical addressing spatial light modulator may further include a transparent front substrate and a back substrate disposed to face each other, wherein the transparent electrode is formed on a surface of the first transparent electrode and the rear substrate disposed on the surface of the front substrate. It may include a second transparent electrode disposed.

The optical addressing spatial light modulator may further include a photosensitive layer disposed on the first transparent electrode, and a liquid crystal layer disposed on the second transparent electrode.

According to one embodiment, the first transparent electrode, the second transparent electrode, the photosensitive layer and the liquid crystal layer may be patterned to form the plurality of divided segments.

According to one embodiment, the wires are a plurality of first wires disposed on the front substrate and electrically connected to respective corresponding first transparent electrodes, and each corresponding second transparent wire disposed on the back substrate. It may include a plurality of second wires electrically connected to the electrodes.

For example, the plurality of first wires and the second wires may be arranged along a gap between the plurality of segments.

In one embodiment, the optical addressing spatial light modulator may comprise a first half and a second half divided about its center, wherein the plurality of first and second wirings comprise the first half and the first half. The first wires and the second wires are distributed in two half portions and are disposed along the gap of the first half portion, respectively, and are connected to the first transparent electrode and the second transparent electrode in the first half portion, respectively. The first wires and the second wires disposed along the gap may be connected to the first transparent electrode and the second transparent electrode in the second half, respectively.

In another embodiment, the wiring line comprises: a plurality of first wiring lines arranged along an outer surface of the front substrate so as to face a region of the first transparent electrode and electrically connected to each corresponding first transparent electrode; And a plurality of second wires arranged along an outer surface of the back substrate so as to face a region of the second transparent electrode and electrically connected to respective corresponding second transparent electrodes.

In this case, an optical addressing spatial light modulator includes a first via hole disposed through the front substrate to electrically connect the plurality of first wires with respective corresponding first transparent electrodes, and the plurality of second wires. And a second via hole disposed through the back substrate to electrically connect with each corresponding second transparent electrode.

On the other hand, a holographic three-dimensional image display device according to another type of the present invention, the recording light source for emitting a recording beam; An electrical addressing spatial light modulator for modulating the recording beam emitted from the recording light source according to the hologram information about the stereoscopic image; A reproduction light source emitting a reproduction beam; An optical addressing spatial light modulator having the above-described structure, receiving the recording beam modulated by the electrical addressing spatial light modulator and modulating the reproduction beam emitted from the reproduction light source according to the hologram information contained in the modulated recording beam; And a scanning optic projecting the recording beam modulated by the electrical addressing spatial light modulator to the optical addressing spatial light modulator.

The holographic 3D image display device may further include a Fourier lens for focusing a reproduction beam modulated by the optical addressing spatial light modulator.

In one embodiment, the electrical addressing spatial light modulator is configured to sequentially modulate a recording beam according to hologram information spatially divided into a plurality of areas corresponding to a plurality of segments of the optical addressing spatial light modulator, wherein the scanning optical The unit may be configured to sequentially project the sequentially modulated recording beams to corresponding segments of the optical addressing spatial light modulator.

Further, the scanning optics may be configured to project the modulated recording beam only within each segment region of the optical addressing spatial light modulator.

On the other hand, the holographic three-dimensional image display method according to another type of the present invention, generating a hologram for the entire stereoscopic image to be finally displayed; Of the holograms for the whole stereoscopic image, only the regions corresponding to the plurality of segments of the optical addressing spatial light modulator are taken and divided into a plurality of sub-holograms, and the regions corresponding to the gaps between the plurality of segments are discarded. step; Optimizing the plurality of sub-holograms; Modulating a recording beam by sequentially providing the optimized sub-holograms to an electrical addressing spatial light modulator; Modulating a reproduction beam by projecting the modulated recording beams onto segments of the optical addressing spatial light modulator corresponding to each sub-hologram; And generating a stereoscopic image by focusing a reproduction beam modulated by the optical addressing spatial light modulator.

The optical addressing spatial light modulator may be an optical addressing spatial light modulator according to the above-described structure.

For example, the hologram is CGH, and the generating of the hologram may be performed by any one of a ping-pong algorithm, a coherent ray tracing method, and a diffraction-specific algorithm.

In one embodiment, the plurality of sub-holograms may be divided into a two-dimensional array identical to the segments of the optical addressing spatial light modulator.

In one embodiment, optimizing the plurality of sub-holograms may comprise binarizing the plurality of sub-holograms with respect to amplitude or with respect to the modulation characteristics of the optical addressing spatial light modulator.

For example, optimizing the plurality of sub-holograms may be performed in any one of an iteration algorithm, a POCS algorithm, and a DBS algorithm.

In one embodiment, the modulated recording beam can be projected only within each segment area of the optical addressing spatial light modulator.

In one embodiment, while projecting the recording beam modulated on the basis of any optimized sub-hologram to the segment corresponding to the sub-hologram, the optimization process is performed on the sub-hologram corresponding to the next segment of the segment. can do.

In addition, of the plurality of segments of the optical addressing spatial light modulator, only a specific segment to which the recording beam is incident may be turned on and the remaining segments may be turned off.

According to the disclosed embodiments, wirings connected to the divided segments of the optical addressing spatial light modulator OASLM may be minimized to minimize gaps between the segments. Therefore, the difference of the gap in the total area of the optical addressing spatial light modulator can be minimized to reduce the influence of the gap.

Further, according to the disclosed embodiments, since the CGH is optimized after dividing to match the divided segments of the optical addressing spatial light modulator, it is possible to save the computation time required for optimization. Moreover, while providing the optimized CGH to the corresponding segment of the optical addressing spatial light modulator, the CGH of the next segment can be optimized, further reducing the computation time required for the generation and optimization of the CGH.

1 is a conceptual diagram schematically illustrating a configuration of a holographic 3D image display device according to an embodiment.
FIG. 2 is a schematic perspective view for describing an operation of the holographic 3D image display device illustrated in FIG. 1.
3 schematically shows an example of dividing a CGH for an entire image into a plurality of sub-CGHs corresponding to a plurality of segment regions.
4 is a perspective view schematically showing an example of projecting a modulated recording beam onto a segment of an optical addressing spatial light modulator OASLM through a scanning optic.
5 is a schematic cross-sectional view of a structure of an optical addressing spatial light modulator (OASLM) according to an embodiment.
FIG. 6 is a plan view exemplarily illustrating an arrangement structure of wires in the optical addressing spatial light modulator OASLM shown in FIG. 5.
7 is a schematic cross-sectional view of a structure of an optical addressing spatial light modulator (OASLM) according to another embodiment.
FIG. 8 is a plan view exemplarily illustrating an arrangement structure of wires in the optical addressing spatial light modulator OASLM shown in FIG. 7.

Hereinafter, an optical addressing spatial light modulator (OASLM) divided into a plurality of segments, a holographic 3D image display apparatus and a method using the same will be described in detail with reference to the accompanying drawings. In the drawings, like reference numerals refer to like elements, and the size of each element in the drawings may be exaggerated for clarity and convenience of description. Meanwhile, the embodiments described below are merely exemplary, and various modifications are possible from these embodiments. In addition, in the layer structure described below, the expressions "upper" or "upper" may include not only directly above and in contact but also above.

1 is a conceptual diagram schematically illustrating a configuration of a holographic 3D image display device according to an embodiment.

Referring to FIG. 1, the holographic 3D image display apparatus 100 according to an exemplary embodiment includes a recording light source 101 emitting a recording beam and hologram information (eg, a CGH signal) divided into a plurality of areas. Electrical modulating spatial light modulator (hereinafter referred to as EASLM) 102 for modulating the recording beam emitted from the recording light source 101, the reproducing light source 105 for emitting the reproducing beam, and the recording modulated by the EASLM 102 An optical addressing spatial light modulator (OASLM) 110 comprising a plurality of segments for receiving the beam and modulating the reproduction beam emitted from the reproduction light source 105 according to the hologram information contained in the modulated recording beam; The scanning optical unit 104 may transmit the recording beam modulated by the EASLM 102 to a corresponding position among the plurality of segments of the OASLM 110. Optionally, the holographic 3D image display apparatus 100 may further include a Fourier lens 107 for focusing a reproduction beam modulated by the OASLM 110 on a predetermined space. In addition, when the EASLM 102 is a reflective type, the EASLM 102 further includes a beam splitter 103 for reflecting the recording beam emitted from the recording light source 101 to the EASLM 102 and transmitting the recording beam modulated by the EASLM 102. can do. Similarly, when the OASLM 110 is a reflective type, the OASLM 110 may further include a beam splitter 106 for reflecting the recording beam emitted from the reproduction light source 105 to the OASLM 110 and transmitting the reproduction beam modulated by the OASLM 110. Can be.

The recording light source 101 may use, for example, a laser that emits coherent light, but may use a general light source without coherence. In addition, in order to increase the resolution of the OASLM 110, the recording light source 101 can emit light having a short wavelength. For example, a blue light source or an ultraviolet light source in the i-line band can be used as the recording light source 101. The reproduction light source 105 may be a coherent light source that emits coherent light, such as a laser. The reproduction light source 105 may emit light of a red wavelength longer than the emission wavelength of the recording light source 101, for example, but this is only one example and the emission wavelength of the reproduction light source 105 is not particularly limited.

The EASLM 102 modulates the recording beam irradiated from the recording light source 101 according to the hologram information. For example, the EASLM 102 may be any one of a digital micromirror device (DMD), a liquid crystal on silicon (LCoS), and a liquid crystal device (LCD). It can be configured to include one. The hologram information provided to the EASLM 102 may be a computer-generated hologram (CGH), and the hologram information spatially divided into a plurality of areas corresponding to the plurality of segments partitioned in the OASLM 110 is sequentially provided to the EASLM 102. It may be provided as.

FIG. 2 is a schematic perspective view illustrating the operation of the holographic 3D image display device 100 shown in FIG. 1. For convenience of description, only the scanning optical unit 104 and the OASLM 110 are shown in FIG. 2, and the rest of the configuration is omitted.

Referring to FIG. 2, the OASLM 110 is divided into a plurality of segments for respectively modulating a reproduction beam. These multiple segments can be arranged in a two-dimensional array of N × M, where N and M are natural numbers greater than one. Further, each segment may include pixels with a very small width, for example about 1 um. As described above, hologram information (eg, a CGH signal) that is spatially divided into a plurality of areas corresponding to the plurality of segments may be sequentially provided to the EASLM 102. For example, the EASLM 102 is sequentially provided with hologram information corresponding to the first segment area S1, the second segment area S2, the third segment area S3, and the fourth segment area S4, respectively. The EASLM 102 may sequentially modulate the recording beam according to the hologram information.

The scanning optics 104 then delivers the recording beams that are sequentially modulated in the EASLM 102 to the corresponding segments on the OASLM 110. For example, the scanning optics 104 provide the recording beam modulated according to the hologram information corresponding to the first segment area S1 to the first segment area S1, and then to the second segment area S2. The recording beam modulated according to the corresponding hologram information is provided to the second segment area S2. In this manner, the scanning optics 104 may scan the recording beams sequentially from the first segment to the last segment of the OASLM 110. Then, the hologram information on the stereoscopic image of one frame may be provided to the OASLM 110. The OASLM 110 modulates the reproduction beam emitted from the reproduction light source 105 based on the hologram information contained in the recording beam incident on the respective segments. The modulated reproduction beam is reflected by the OASLM 110 and projected onto a predetermined space, thereby forming a stereoscopic image of one frame. Optionally, a stereoscopic image may be generated on the focal point of the Fourier lens 107 by focusing the modulated reproduction beam with the Fourier lens 107.

When the hologram information is CGH, as described above, the higher the resolution of the stereoscopic image and the wider the viewing angle, the greater the amount of computation required to generate and optimize the CGH. In this embodiment, considering the fact that there is a gap between the segments of the OASLM 110, it is possible to reduce the amount of calculation required for the optimization of the CGH. That is, although only a simple line is shown in FIG. 2, there is a gap between the segments of the OASLM 110 which cannot modulate the reproduction beam. As a result, even if a recording beam containing hologram information enters such a gap, the portion of the hologram corresponding to the gap does not contribute to the modulation of the reproduction beam. Therefore, if only the regions of the CGH corresponding to the segments of the OASLM 110 are optimized and the regions of the CGH corresponding to the gap are ignored, the amount of computation required for the optimization can be reduced accordingly. For example, the area occupied by the gap in the total area of the OASLM 110 may be about 1%, and according to the present embodiment, the amount of calculation required to generate the optimized hologram information may be reduced by about 1%.

The process of generating the optimized hologram information according to the present embodiment is as follows. First, a hologram such as CGH for an entire stereoscopic image to be finally displayed by the holographic 3D image display device 100 is generated using a computer based on an optical theory. The generated CGH is, for example, an interference pattern projected on a two-dimensional plane having the same aspect ratio as the OASLM 110, and includes information on the intensity and phase of the wave. Various methods for effectively generating CGH that accurately reflect stereoscopic images have been disclosed. For example, CGH can be generated using methods such as a ping-pong algorithm, coherent ray trace, diffraction-specific algorithm, and the like.

Thereafter, the CGH of the entire image generated as above is divided into a plurality of sub-CGHs corresponding to the plurality of segments of the OASLM 110. For example, referring to FIG. 3, in the CGH 10 of the whole image, only the regions corresponding to the plurality of segments of the OASLM 110 are taken and divided into the plurality of sub-CGHs 11, and the segments are divided. The region 12 corresponding to the gap between them is discarded. Thus, the plurality of sub-CGHs 11 may be arranged in a two-dimensional array of N × M like the segments of the OASLM 110.

The multiple sub-CGHs 11 thus obtained are provided to the EASLM 102 in turn, and can be used to modulate the recording beam in a predetermined pattern. Then, the recording beam modulated based on the particular sub-CGH 11 may be projected through the scanning optics 104 to the segment of the OASLM 110 corresponding to the sub-CGH 11. However, the optimization process may be performed on the plurality of sub-CGHs 11 before performing this operation. The optimization process is a process for matching the actual stereoscopic image that is finally formed through the OASLM 110 (or the OASLM 110 and the Fourier lens 107) with the target image. Through the optimization process, the error generated when generating the CGH 10 for the entire image is corrected, and the loss of information generated when the CGH 10 is divided into a plurality of sub-CGHs 11 is compensated for, In addition, the error due to the modulation characteristics of the EASLM 102 and OASLM 110 can be compensated. By using the optimized sub-CGH 11, it is possible to reproduce the entire image as it is, even if the sub-CGH 11 do not include information of the area corresponding to the gap between the segments of the OASLM 110.

In particular, the optimization process may be important when the OASLM 110 is not a modulator capable of performing both phase modulation and amplitude modulation. As described above, the hologram information in the CGH 10 includes information about light intensity and phase. Therefore, in order to form an accurate stereoscopic image, it is advantageous that the OASLM 110 performs both phase modulation and amplitude modulation. However, instead of using a modulator capable of performing both phase modulation and amplitude modulation, it may be practical to use a phase modulator capable of performing only phase modulation or an amplitude modulator capable of performing only amplitude modulation. Errors caused by using an amplitude modulator or phase modulator can be compensated for by the optimization process. By performing an optimization process, a binary amplitude modulator that modulates the intensity of the reproduction beam only in the 'light' and 'dark' states, or a binary phase that modulates the phase of the reproduction beam only to '0 °' or '180 °' Modulators can also be used.

Various algorithms for performing this optimization process are disclosed. For example, the optimization process may be performed on a plurality of partitioned sub-CGHs 11 using methods such as iterative algorithms, projection onto constrained sets (POCS) algorithms, and direct binary search (DBS) algorithms. Can be done. If the OASLM 110 is a binary amplitude modulator or a binary phase modulator, the sub-CGHs 11 may be binarized with respect to amplitude or with respect to the phase through the above algorithm. According to the present embodiment, assuming that the area occupied by the gap is about 1% of the total area of the OASLM 110, since the sub-CGHs 11 do not include the area corresponding to the gap, the amount of calculation necessary for optimization is determined. You can save about 1%.

The sub-CGHs 11 optimized in the above manner are sequentially provided to the EASLM 102 and used to modulate the recording beam in a predetermined pattern. Then, the recording beam modulated in turn on the basis of the optimized sub-CGHs 11 is sequentially projected onto the segment of the OASLM 110 corresponding to each sub-CGH 11 through the scanning optics 104. Can be. At this time, as shown in FIG. 4, the scanning optics 104 accurately project the modulated recording beam only to the corresponding segment S of the OASLM 110. That is, the scanning optics 104 can be configured such that the modulated recording beam is projected only on the region of a particular segment S and not to the gaps G around the segment S. This is because the modulated recording beam has only hologram information of the area corresponding to the segment S and no hologram information of the area corresponding to the gap.

Meanwhile, according to the present exemplary embodiment, the process of optimizing the sub-CGHs 11 and the process of projecting the modulated recording beams may be simultaneously performed. For example, while projecting a recording beam modulated based on one optimized sub-CGH 11 to a segment corresponding to that sub-CGH 11, the sub-CGH (corresponding to the next segment of that segment ( 11) can be optimized. Then, after optimizing all the sub-CGHs 11, it is possible to save time for displaying a stereoscopic image than to modulate and project the recording beams.

In this manner, the scanning optics 104 may sequentially scan the recording beams to all segments of the OASLM 110. While the recording beam is being projected, only the specific segment on which the recording beam is incident may be turned on and the remaining segments may be in the off state. For example, referring back to FIG. 2, first, the first segment region S1 is turned on and the remaining segments are turned off. At the same time, a recording beam containing information of the sub-CGH 11 corresponding to the first segment area S1 is projected onto the first segment area S1 through the scanning optical unit 104. Subsequently, while the second segment region S2 is turned on and the remaining segments are turned off, a recording beam containing information of the sub-CGH 11 corresponding to the second segment region S2 is scanned. Through the second segment area S2. In this manner, recording beams containing information of the sub-CGH 11 corresponding to each of the segments from the first segment to the last segment can be projected in turn.

Here, the OASLM 110 may be configured to be reset only at the moment of turning on and to maintain the current state even when turned off. That is, while the recording beam is projected on the next segment, the previous segment maintains the modulation state by the corresponding recording beam. For example, while the recording beam is projected on the second segment area S2, even if the first segment area S1 is turned off and the recording beam is no longer incident, the first segment area S1 is not reset and is recorded. The state when the beam is projected can be maintained as it is.

For the on / off operation of each segment, a transparent electrode such as ITO and a wiring may be disposed in individual segments of the OASLM 110, respectively. The difference from the EASLM 102 is that, in the case of the EASLM 102, the transparent electrode is individually disposed for each pixel, but in the case of the OASLM 110, the transparent electrode is individually disposed for each segment, and a plurality of electrodes in each segment are provided. The driving of the pixels is controlled by the incidence of the recording beam. In the conventional case, a plurality of vertical electrodes and a plurality of horizontal electrodes are formed on the front substrate and the rear substrate, respectively, so that only segments at positions where the vertical and horizontal electrodes to which voltage is applied are turned on and the remaining segments are turned off It became. However, since one vertical electrode and the horizontal electrode are in contact with a plurality of segments, there is a possibility that some pixels in the turned-off segment may malfunction.

In this embodiment, the individual segments of the OASLM 110 are each independently turned on / off to perform the correct operation. That is, according to the present embodiment, without using a plurality of vertical electrodes and a plurality of horizontal electrodes that cross each other, a separate separate transparent electrode and independent wiring electrically connected to the transparent electrodes can be allocated to each segment. Can be. When using these independent electrode and wiring structures, it may be advantageous to minimize the gap between the segments.

For example, referring to the schematic cross-sectional view of FIG. 5, the OASLM 110 may include a transparent front substrate 111, a rear substrate 112, and a first transparent electrode disposed on a surface of the front substrate 111. 113, a second transparent electrode 114 disposed on the surface of the rear substrate 112, a photosensitive layer 115 disposed on the first transparent electrode 113, and a second transparent electrode 114 disposed on the second transparent electrode 114. The liquid crystal layer 116 may be included. The liquid crystal layer 116 and the photosensitive layer 115 may be disposed to be in direct contact with each other, but a mirror layer for reflecting light may be further disposed between the liquid crystal layer 116 and the photosensitive layer 115.

In the structure of the holographic three-dimensional image display device 100, the photosensitive layer 115 is disposed toward the EASLM 102 and the liquid crystal layer 116 is disposed toward the Fourier lens 107. When a voltage is applied to the transparent electrodes 113 and 114, if a recording beam does not enter the photosensitive layer 115, the resistance of the photosensitive layer 115 is large, so that most voltage drops occur in the photosensitive layer 115. Thus, since the liquid crystal layer 116 is in an off state, the arrangement of liquid crystals in the liquid crystal layer 116 does not change. On the other hand, when the recording beam is incident on the photosensitive layer 115, the resistance of the photosensitive layer 115 is reduced, most of the voltage drop occurs in the liquid crystal layer 116. Then, as the liquid crystal layer 116 is turned on, the arrangement of liquid crystals in the liquid crystal layer 116 may be changed. In this manner, the OASLM 110 may modulate the reproduction beam incident toward the liquid crystal layer 116.

The first transparent electrode 113, the second transparent electrode 114, the photosensitive layer 115, and the liquid crystal layer 116 may be patterned to form a plurality of segments. An insulating layer 117 may be disposed in the gap between the segments. However, only the transparent electrodes 113 and 114 are patterned, and the photosensitive layer 115 and the liquid crystal layer 116 may be continuously formed without being separated without the insulating layer 117. The transparent electrodes 113 and 114 in one segment are completely separated from the transparent electrodes 113 and 114 in the other segment and are patterned in the same shape as that of the segment. In this structure, as shown in FIG. 5, a plurality of wirings 118 and 119 for applying a voltage to each of the transparent electrodes 113 and 114 are provided with the front substrate 111 and the rear substrate 112 in the gap region. May be arranged respectively. For example, the plurality of first wirings 118 are disposed on the front substrate 111 and electrically connected to the first transparent electrode 113 corresponding thereto, and the plurality of second wirings 119 are rear substrates. Disposed on 112 and electrically connected to a corresponding second transparent electrode 114.

However, when the number of segments is large, the size of the gap may increase as the number of wirings 118 and 119 disposed in the gap increases. FIG. 6 is a plan view illustrating an arrangement structure of the wirings 118 and 119 to minimize the size of the gap, and schematically shows only the front substrate 111, the first transparent electrode 113, and the first wiring 118. It is showing. Referring to FIG. 6, a plurality of first transparent electrodes 113a and 113b are arranged in a two-dimensional array on the front substrate 111. The arrangement of the first transparent electrodes 113a and 113b is the same as that of the segments. A plurality of first wires 118a and 118b are arranged along the gap, and are connected to the first transparent electrodes 113a and 113b respectively.

According to the present embodiment, as shown in FIG. 6, the OASLM 110 is divided into an upper half and a lower half based on the center thereof, and the first wirings 118a and 118b are distributed in the gap between the upper half and the lower half, respectively. Can be placed. The first wirings 118a disposed along the gap of the upper half are connected only to the first transparent electrodes 113a in the upper half, and the first wirings 118b disposed along the gap of the lower half are first It is connected to only the transparent electrodes 113b. Then, the number of first wirings 118a disposed in one gap can be reduced by half. For example, when ten segments are arranged along the longitudinal direction, five first wirings 118a are respectively disposed in the gaps of the upper half and the gaps of the lower half without arranging all ten wirings 118 in one gap. 118b) can be distributed and arranged. Although only the front substrate 111, the first transparent electrode 113, and the first wiring 118 are shown in FIG. 6, the back substrate 112, the second transparent electrode 114, and the second wiring 119 are not shown. The same can be applied to. In FIG. 6, the OASLM 110 is divided into an upper half and a lower half, but the first wirings 118a and 118b may be arranged by dividing the OASLM 110 into an upper half and a lower half. In this case, the first wirings 118a and 118b may be arranged in the horizontal direction instead of the vertical direction.

In addition, as illustrated in the cross-sectional view of FIG. 7, a plurality of wires 118 and 119 may be disposed on the outer surfaces of the front substrate 111 and the rear substrate 112, respectively. In this case, since the wirings 118 and 119 are not disposed in the gap, the size of the gap can be further reduced. For example, referring to FIG. 7, a plurality of first wires 118 are arranged along the outer surface of the front substrate 111 to face an area of the first transparent electrode 113. The plurality of first wires 118 may be electrically connected to the corresponding first transparent electrodes 113 through the first via holes 118 ′ penetrating the front substrate 111. Similarly, a plurality of second wirings 119 may be arranged along the outer surface of the back substrate 112 to face the region of the second transparent electrode 114, and the second via hole penetrating the back substrate 112. Each of the second transparent electrodes 114 may be electrically connected to each other through the reference numeral 119 ′.

As shown in the plan view of Fig. 8, in this case, since the wirings 118 and 119 are not disposed along the gap, it is not necessary to divide and disperse the wirings 118 and 119 into the upper half and the lower half. In FIG. 8, only the rear substrate 112 and the second wiring 119 are shown for convenience, and the second transparent electrode 114 covered by the rear substrate 112 is indicated by a dotted line. Referring to FIG. 8, a plurality of second wires 119 may be in contact with each corresponding second transparent electrode 114 through the back substrate 112 while traveling from top to bottom.

Thus far, an exemplary embodiment of an optical addressing spatial light modulator (OASLM) divided into a plurality of segments, a holographic three-dimensional image display apparatus and a method using the same, has been described and illustrated in the accompanying drawings in order to facilitate understanding of the present invention. . However, it should be understood that such embodiments are merely illustrative of the invention and do not limit it. And it is to be understood that the invention is not limited to the illustrated and described description. This is because various other modifications may occur to those skilled in the art.

100 .... Holographic 3D Video Display 101 ..... Recording Light Source
102 ... Electric Addressing Spatial Light Modulator (EASLM)
103, 106 ..... beam splitter 104 ..... scanning optics
105 ..... Playback light source 107 ..... Fourier lens
110 ..... Optical addressing spatial optical modulator (OASLM)
111 ..... Front substrate 112 ..... Rear substrate
113, 114 ..... transparent electrode 115 ..... photosensitive layer
116 ... liquid crystal layer 117 ... insulation layer
118, 119 ..... wiring

Claims (21)

A plurality of segmented light modulation segments arranged in a two dimensional array;
A gap formed between the plurality of segments; And
A plurality of independent first transparent electrodes respectively corresponding to the plurality of segments;
A plurality of independent second transparent electrodes respectively corresponding to the plurality of segments;
A plurality of independent first wires respectively corresponding to the plurality of first transparent electrodes; And
And a plurality of independent second wires respectively corresponding to the plurality of second transparent electrodes.
The first and second transparent electrodes corresponding to one segment are separated from the first and second transparent electrodes corresponding to the other segment, each first wiring being electrically connected only to the corresponding first transparent electrode, Each second wiring is electrically connected only to a corresponding second transparent electrode. The method of claim 1,
The optical addressing spatial light modulator further comprises a transparent front substrate and a rear substrate disposed facing each other,
The first transparent electrode is disposed on a surface of the front substrate, and the second transparent electrode is disposed on a surface of the rear substrate,
The optical addressing spatial light modulator further comprises a photosensitive layer disposed on the first transparent electrode, and a liquid crystal layer disposed on the second transparent electrode. The method of claim 2,
And the first transparent electrode and the second transparent electrode are patterned to form the plurality of divided segments, and the photosensitive layer and the liquid crystal layer are continuously formed without being separated. delete The method of claim 1,
And the plurality of first and second wirings are arranged along a gap between the plurality of segments. The method of claim 5,
The optical addressing spatial light modulator comprises a first half and a second half divided about its center;
The plurality of first wires and the second wires are distributed to the first half and the second half,
First and second wirings disposed along the gap of the first half portion are respectively connected to the first and second transparent electrodes of the first half portion, and the first wirings disposed along the gap of the second half portion. And the second wirings are respectively connected to the first transparent electrode and the second transparent electrode in the second half. The method of claim 2,
The first wiring is arranged along an outer surface of the front substrate so as to face an area of the first transparent electrode,
And the second wiring is arranged along an outer surface of the back substrate so as to face a region of the second transparent electrode. The method of claim 7, wherein
A first via hole disposed through the front substrate to electrically connect the plurality of first wires to each corresponding first transparent electrode, and the plurality of second wires to each corresponding second transparent electrode; And a second via hole disposed through said back substrate to electrically connect. A recording light source for emitting a recording beam;
An electrical addressing spatial light modulator for modulating the recording beam emitted from the recording light source according to the hologram information about the stereoscopic image;
A reproduction light source emitting a reproduction beam;
An optical addressing spatial light modulator according to claim 1, for receiving a recording beam modulated by the electrical addressing spatial light modulator and modulating a reproduction beam emitted from the reproduction light source according to hologram information contained in the modulated recording beam; And
And a scanning optical unit for projecting the recording beam modulated by the electrical addressing spatial light modulator to the optical addressing spatial light modulator. The method of claim 9,
And a Fourier lens for focusing the reproduction beam modulated by the optical addressing spatial light modulator. The method of claim 9,
The electrical addressing spatial light modulator is configured to sequentially modulate a recording beam according to hologram information spatially divided into a plurality of areas corresponding to a plurality of segments of the optical addressing spatial light modulator,
And the scanning optics is configured to sequentially project the sequentially modulated recording beams to corresponding segments of the optical addressing spatial light modulator. The method of claim 11,
And the scanning optics are configured to project the modulated recording beam only within each segment region of the optical addressing spatial light modulator. Generating a hologram about a final stereoscopic image to be finally displayed;
Of the holograms for the whole stereoscopic image, only the regions corresponding to the plurality of segments of the optical addressing spatial light modulator are taken and divided into a plurality of sub-holograms, and the regions corresponding to the gaps between the plurality of segments are discarded. step;
Optimizing the plurality of sub-holograms;
Modulating a recording beam by sequentially providing the optimized sub-holograms to an electrical addressing spatial light modulator;
Modulating a reproduction beam by projecting the modulated recording beams onto segments of the optical addressing spatial light modulator corresponding to each sub-hologram; And
And focusing the reproduction beam modulated by the optical addressing spatial light modulator to generate a stereoscopic image.
The optical addressing spatial light modulator is a holographic three-dimensional image display method according to claim 1. delete The method of claim 13,
The hologram is CGH,
The generating of the hologram is performed by any one of a ping-pong algorithm, a coherent ray tracing method, and a diffraction-specific algorithm. The method of claim 13,
And said plurality of sub-holograms are divided into a two-dimensional array identical to the segments of said optical addressing spatial light modulator. The method of claim 13,
Optimizing the plurality of sub-holograms comprises binarizing the plurality of sub-holograms with respect to amplitude or with respect to phase in accordance with the modulation characteristics of the optical addressing spatial light modulator. The method of claim 13,
The optimizing of the plurality of sub-holograms is performed by any one of a repetition algorithm, a POCS algorithm, and a DBS algorithm. The method of claim 13,
And said modulated recording beam is projected only within each segment region of said optical addressing spatial light modulator. The method of claim 13,
Holographic three-dimensional that performs an optimization process on the sub-hologram corresponding to the next segment of the segment while projecting the recording beam modulated on the basis of one optimized sub-hologram to the segment corresponding to the sub-hologram Video display method. The method of claim 13,
Among the plurality of segments of the optical addressing spatial light modulator, only a specific segment to which a recording beam is incident is turned on and the remaining segments are in an off state.

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